Shares of Microsoft Corp. closed Monday at $40.99, the highest level since July 2000. The stock is up 9.6% this year, a rally that has coincided with the arrival of new CEO Satya Nadella early last month. That’s heartening, especially considering the 40% drop in market value that Microsoft suffered during the 14-year tenure of previous CEO Steve Ballmer.

As WSJ’s Dan Gallagher reported, Mr. Nadella is off to a good start. He made his first public showing at a small press event in San Francisco last week to launch the company’s popular Office suite for Apple Inc.'s iPad. He also announced new services designed to help companies manage fleets of mobile and PC devices regardless of operating system.

A more important test comes this week, as the company kicks off its annual Build developers’ conference. Historically, this is where Microsoft previews forthcoming updates to its Windows operating system, and lately has included announcements of new devices as well.

Gallagher joins digits to preview the event and to analyze just how much longer Mr. Nadella can keep the good times rolling.